﻿<p>The <em>IfcSIUnit</em> covers both standard base SI units such as meter and second, and derived SI units such as Pascal, square meter and cubic meter.</p>

<blockquote class="extDef">
NOTE&nbsp; Definition according to ISO/CD 10303-41:1992<br>
An SI unit is the fixed quantity used as a standard in terms of which items are measured as defined by ISO 1000 (clause 2).</blockquote>

<blockquote class="note">
NOTE&nbsp; Corresponding ISO 10303 name: si_unit, please refer to ISO/IS 10303-41 for the final definition of the formal standard.
</blockquote>

<blockquote class="history">
HISTORY&nbsp; New entity in IFC1.5.1.
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